Thursday, 29 October 2009

Many people have told me they know which song they want played at their funeral, but few have ever had a preference for songs to play at their birth. Ok, both are a bit strange, one you can't do because it's in the past and one you won't be around to enjoy anyway.

Of course, some would argue that the choice of music should really be left to the mother. Dr. Jeni Worden has some advice on up-beat tracks for mothers, but can have some have mixed results, for example:

I spent the early part of my labour making a mixed tape of Motown, hip hop and rock to keep me energised. While this worked when I had been labouring relatively pain-free for eight hours, I wanted to destroy it as violently as possible when I was exhausted ten hours later.

This illustrates a difference between birth and death songs. While a 12 minute guitar solo might seem a bit indulgent at a funeral, there's a lot more scope for a birth song. Wagner's Ring Cycle wouldn't be totally out of the question. At any rate, choosing a song for the 'big moment' is still tricky. A balance must be struck between the rock and roll celebration of life and the choir-of-angels pretension.

In the end (or is it the beginning?), I'd like to come out rocking. Here are some songs I'd like to emerge to (unfortunately I've taken this rather seriously and none of them are funny puns):

Wednesday, 28 October 2009

Sound symbolism describes a ‘natural’ connection between sound and meaning. For example, it has been noted that many words which sound the same also have similar meanings (e.g. Point, poke, pike, peg, pierce, prick, prod, probe). The idea is that some meanings (like the pointyness of the example words) lend themselves more naturally to certain sounds (like the explosive 'p' of the example words). It's been a contravertial theory, especially when applied accross languages towards explaining the origins of language (e.g. Rammachandran and Hubbard's synaesthetic bootstrapping hypothesis). More recently, the topic of 'ideophones' has take over.

It's fun to think of more examples, but here's a study I did a little while ago:

Sound symbolism may be felt most with very visceral words. Hurford (2007) suggests that words for ‘urine’ and ‘faeces’ should sound different across languages. Specifically, 'urine' words should have higher vowels to match the high pitch of pissing, (e.g. 'pee') while 'faeces' words should have lower vowels to match the bass sounds of the behind (e.g. 'poo').

Who said Linguists were always high-minded?

I tested this theory by finding Words for ‘urine’ and 'faeces' in 29 languages, including ones from Europe, Africa, North America, South America, Asia, Austral Asia, Australia and the Pacific islands. There was a bias towards selecting 'childish' or child-directed words over clinical terms (e.g. 'poo' over 'faeces') following arguments for the primacy of childish language (Cytowic 1995). Here are the results:

Words With...

Urine

Faeces

High Front Vowels Only

26

5

No high front vowels

7

32

Mixed vowel types

12

5

Total

45

42

There were significantly more words for urine with high front vowels than for faeces (Chi-Squared = 33.07, df = 2, p <>

Monday, 26 October 2009

People worry that Capitalism and Technology will force everyone into a monoculture, destroying the idiosyncrasies of local cultures and languages. Here, I argue that, although these factors my cause people's cultures to grow increasingly closer, people's languages may diverge. This argument will take us to the North-West coast of India, but first, to a not-so-distant future.

In Jim Hurford's mini Sci-Fi Desperanto is set in a future society where people use lators - small devices which translate speech from one language into another - to speak to people outside their social group. Over time, language packs have been added so that anyone can speak to anyone else through them, even between dialects. This means that the languages of each little community are cut off from each other, leaving them free from the pressure to conform. The result is an explosion of diversity in languages.

The lators are used for trade between groups. However, similar systems may not be so futuristic.

Alastair Sussock was telling me about his Weather Insurance project for the IFMR Centre for Microfinance. It's an assessment of how farmers in the state of Gujarat, India, approach the idea of buying insurance against crop failure due to bad weather. Gujarat has an unstable climate where years of good rainfall will be punctuated by severe droughts, and weather insurance would help spread this risk. However, farmers were initially resistant to the idea of paying for a service which may not materialise. In the report, Sussock identifies 'financial literacy' as a major pitfall for the sale of insurance.

Indeed, his next project looked at how a mobile SMS system for disseminating local economic information would affect the farmers. There is a high degree of inefficiency in local markets, due to the farmers not being sure what price they will receive for their goods in which market towns. SMS farming is a system whereby farmers receive information about the prices of goods in various locations (e.g. 60 Rupies for 10kg of Cabbage in Ahmedabad) so they can best judge where to sell it and for how much. There are already several services set up (e.g. here), and many seem to be succeeding (here).

The idea is that farmers can optimise their business decisions, increasing profit and lowering prices. Armed with this financial knowledge, farmers are less dependent on social networks for information.

Daniel Nettle identifies ecological risk as a major factor in linguistic diversity. Where the environmental conditions are more variable and self-sufficiency is more difficult (e.g. a dessert/floodplain), groups must form close social bonds with each other in order to spread the risk of ruin. In this situation, it's more likely that linguistic norms are adopted by networked groups and, over time, everybody ends up speaking the same language. On the other hand, in ecologies where self-sufficiency is easy, there is less need to form close social bonds with other groups, therefore the languages will remain separate. Indeed, Nettle (1999) finds direct correlations between ecological risk and linguistic diversity.

Importantly, languages will only converge when groups have close social bonds with other, distant groups. Although the SMS technology may be expanding people's social networks, the new links are domain-specific and loose. Therefore, the introduction of ecological insurance and a centralised technical lingo for economics may have interesting effects on the linguistic diversity of India. If the ecological risk can be reduced by insurance, and the inter-group dependence and linguistic communication reduced through the SMS service, then the languages of individual groups will become increasingly isolated. This may, as Nettle and Hurford predict, lead to a diversification of language.

Although farmers across India may come to share a common financial language, the languages and dialects they use with those in their closest social circles will remain their own.

Sunday, 25 October 2009

As I tried to think of anything else except the searing pain in my quads at my last Kung Fu class, I started wondering about how martial arts are taught. The master gradually imparts a very stratified sequence of movements, called the form, to a student who then repeats them over and over. Importantly, the master tries to minimise the idiocyncracies in the student's form - a slightly arched back, irregular timing, poor balance etc. Because of this, I was wondering how much variation there is between different schools paracticing the same forms. Do different masters have different 'accents'?

The approach of most martial arts is specifically set up in order to minimise this. Eugen Herrigel, a german proffesor of philosophy living in Japan, describes his attempt to master the art of Archery. He claimed that, although the initial repetition of movements isolated from application was frustrating, he eventually experienced a 'direct transference of the spirit' from his master (from Singleton, 1998). How about that for anyone doubting the fidelity of memetic transfer?

The theory of evolution states that, in order for a system to improve, there must be variation and competition. In martial arts there is literal competition between sparring partners and in organised events. The best sequences will be selected. However, the system of teaching is set up so only the highest ranking teachers can alter and add to the form. This seems sensible, since changes are likely to improve the form, but it sacrificies improvements that could be found by chance.

Can we learn anything about the cultural transmission of language by studying the way form is transferred from master to student? Moscato (1989) in one of the first articles on memetic algorithms argues that Martial Arts is indeed a good candidate for the study of complex adaptive systems:

The form, like a chromosome, is not an indivisible entity. It is composed of a sequence of defensive and aggressive sub-units which can also be divided, a pattern that resembles the structure of chromosomes, genes and alleles. But within the form there are some movements which can be understood as an indivisible unit, and these are the ones that are really important. The whole is a support to let the brain transform them as reflexes that can be automatically triggered in real combat. The individuals can compute their fitness function by the evaluation of their performance in the execution of the movements of the forms and with some tournaments where they compete.

Moscato points out that most primates, including unskilled humans, tend to fight in an unorganised way while a martial art teaches one to use simple, efficient movements. This might be compared to the chimpanzee Nim's ramblings 'give orange me give eat orange me eat orange give me eat orange give me you' compared to a human's utterance ('give me the orange'). The martial art from may have a 'syntax' in the sense that the order of moves is very important.

However, there are several problems with using martial arts to study language. First, an estimation of the amount of variation in martial arts forms would be necessary. In lieu of excellent historical records, the best estimation would be reached by a comparative approach. This would involve the codification of forms then comparisons to find underlying structures. In other words, the whole problem of linguistics in the first place, and not obviously easier than for languages.

Secondly, it's not clear that martial arts has a semantics. In fact, the moves are not signals used for communication, but coercive actions.

Saturday, 24 October 2009

I recently read Neal Stephenson's Anathem. Amazing, just like his Baroque Cycle, Cryptonomicon and Snowcrash. Although I'd love to see a movie adaptation, I realise that they are probably too complicated and too niche to ever get to Hollywood. Then, I found a trailer for Anathem online. But it wasn't for a movie, it was for the book:

I'd never heard of book trailers before. Seeing it after reading it was weird - some characters were different than I had imagined, but the re-construction of the fight scene is done word-for-word. I'm not sure how I feel about this. It had fairly high production values, and it was quite cool to see how other people visualised the scences. However, there's always the danger of being dissapointed by another person's idea of the book. For example, although I loved Phillip Pullman's His Dark Materials trilogy, I didn't much like the look and feel of the film.

However, at least with a film converstion, you have a chance to read the book first. Could book trailers start limiting our imaginaitons? Am I sounding a bit like an old person? Maybe. I started looking for other book trailers.

Although I couldn't find any other high-quality productions, I quite enjoyed the trailer for the children's book How to Save Your Tail, a re-telling of the 1001 Arabian Nights. It actually made me want to read the book. Brad Meltzer's trailer was also good fun, and looked like it was just made for fun too.

However, most of them were just text, pictures and a voice over (lamented by Phyllis Miller). Some have the tell-tale Windows Moviemaker blue background, others are a bit more snazzy, but ultimately are no more informative than a back-cover blurb. I found this one particularly annoying.

It turns out that book trailers are not a new thing. Here's an article from 2006 which discusses the difficulty of presenting images without influencing the way people percieve their characters. In a more recent post, Jonathan Fields argues that book trailers don't work because marketing advisors don't understand that a straight-up commercial approach won't get a trailer to go viral.

Actually, I quite like the idea, and hope it catches on. I'll be keeping an eye out for book trailers in the future.

Evolutionary approaches have recently been adopted to try to explain the differences in adult and child second language acquisition (SLA). Hagen (2008) uses Paradis's (2004) theory of implicit and explicit learning to argue that adult SLA was selected out because it was not useful to our early ancestors. However, this order of evolution seems unlikely and a more parsimonious and longer-term explanation can be achieved by looking at the differing social pressures of adults and children.

Children acquire languages rapidly, effortlessly, implicitly and fluently. Adults, on the other hand, find second language acquisition laborious, difficult, and often do not achieve native fluency. Hagen (2008) addresses this difference from an evolutionary perspective. Firstly, Hagen shows that the difference between adult and child SLA is physical. Evidence comes from studies of SLA, and anthropology, which shows that the language faculty co-evolved with the physical evolution of our species. This part is well argued, and contains a diverse sources which, rightly, place the problem of the critical period as an evolutionary adaptation to the environmental conditions of the ancestors of humans.

Hagen cites Paradis’ (2004) theory of implicit and explicit knowledge being linked to procedural and declarative memory respectively. Procedural memory stores knowledge of unconscious, automatic skills such as walking. Declarative memory stores knowledge that can be consciously accessed, but with greater difficulty. The ability to incorporate knowledge into procedural memory atrophies in adults, which explains differences in loci of adult second languages in the brain. Hagen’s explanation for Bilingualism, however, focuses on relatively recent, certainly post-linguistic, environmental pressures. The main section of his argument considers the pros and cons of the ability for adult SLA. For the negative effects, Hagen cites Dyson’s (1979) argument that language diversity evolved to establish and maintain cultural differences between competing groups. This resonates with Accommodation theory. The benefits are mainly restricted to the ability for trade.

Hagen argues, however, that adult SLA would generally not be advantageous in pre-agricultural society (low populations dispersed widely). He links the critical period with studies of predatory animals brought up in captivity who don’t develop predatory behavior. As Hagen puts it, “If you don’t acquire it early, you might as well not acquire it at all” (p. 58). Hagen concludes that, since violent conquest of another culture yields greater rewards than cooperation during lean times, there was no pressure to develop adult SLA. On the other hand, the ability to socialize is vital to survival in a human society, so child acquisition is selected for.

Hagen’s explanation comes down to a discussion of the nature of man. Hagen argues that evolution, and evidence from history, favours an aggressive nature rather than an egalitarian one. Learning an enemy’s language is more costly and less beneficial than conquering them.

There are problems with Hagen’s approach, however. Although Hagen stresses that the differences between adult and child acquisition are physical, the explanation relies on sociological factors, originating less than 80,000 years ago. That is, although human language acquisition behaviour seems to “fit rather nicely into the mosaic of evolutionary theory”, Hagen has not explained the pressures that would cause the structural changes in the brain that would lead to differentiation in the first place. In the first half of the paper, Hagen suggests that adults lose their ability to acquire languages for two reasons: Firstly due to general cognitive aging. Secondly, because the language faculty is built upon the same instincts that lead to any young animal learning basic survival skills such as walking, and has therefore never been useful at later stages.

Part of the problem is that Hagen seems to be suggesting that SLA was selected against in adults (noted by Hirchfield, 2008, with a rebuttal by Hagen). That is, there was a point when language learning was equal for adults and children, and the adult ability eroded by drift. If this original adult ability was identical to the child ability (that is, there was no change over a lifetime), this seems to run against the idea that child and adult acquisition are physically different. An alternative situation is where adult and child learning was originally different, but achieved the same goal. This seems an inefficient solution.

Rather than a loss of an ability, perhaps the structural differences between adult and child acquisition reflect adaptations to different tasks. MacWhinney (2007, p. 2) argues the following: Children need to learn language for socialising in order to obtain protection and to inherit knowledge about how to survive. Adults face a different task – they must socialise in order to secure mates and provide for their children. Whereas there would be a pressure for children to acquire basic knowledge about the world (how to walk, red berries are poisonous) and how to communicate with their group, there would be a pressure on adults to keep track of social relationships (e.g., who is sleeping with who) and communicate about resources (e.g., where the food is, organisation of hunting).

I argue that this difference in social pressures is supported by two different kinds of memory: semantic memory, which encodes facts separated from context (e.g. the sky is blue), and episodic memory, which also encodes temporal information (e.g. it rained yesterday). Semantic memory has been argued to be related to procedural memory rather than declarative memory (Hurford, Flaherty & Argyropoulos, 2007). At any rate, it is certainly evolutionarily older than episodic memory, if not unique to humans, and develops later in childhood.

Adults can use the contextual informtion of episodic memory to keep track of complex social interactions. For example, it may be a bad idea to have a general sense that ‘X is a nice guy’, if X is nice only two thirds of the time. However, rather than an erosion of procedural/semantic memory in adults, it is the development of declarative/episodic memory that may be overriding procedural/semantic memory during adult second language acquisition.

I propose that the balance between using semantic and episodic memory was selected for so that semantic memory was favoured in childhood and episodic memory was favoured in adulthood. To test this assumption, a model was run to examine the ratios of semantic and episodic memory in a population of agents who age and compete for mating opportunities by assessing the social interactions of others.

The ModelIn this model, agents can interact and store knowledge about events in either a procedural or declarative mode. Adults must keep track of how others behave in order to maximise their chances of offspring. It is hypothesised that this pressure will cause adults to use their declarative memory more than children.

AgentsEach agent is either male or female and has an age and an energy level. Each also has a set of genes that define a linear model for making decisions. That is, each variable involved in a decision can be modified by a slope and intercept with which to modify it. Agents receive energy at each time step (i.e. they eat) as long as they are above a certain age (they are initially dependent on others). Agents become capable of reproduction after a certain age with a small random variation. Agents can die either because they run out of energy or from old age.

KnowledgeEach agent has a declarative and procedural memory store which can store pieces of knowledge. A piece of knowledge can be either reflexive – another agent did something to me – or transitive – two other agents interacted with each other. The piece of knowledge also contains an attitude – whether the interaction was good or bad. For instance, a piece of knowledge can represent “Agent X gave me food”, or “Agent X and Agent Y mated”.

MemoryThe declarative/episodic store is a LILO stack with a limited capacity. New pieces of knowledge are added to the start of the stack. This models episodic memory (e.g. “I gave Agent X some food earlier, but then they refused to mate with me”). The procedural/semantic memory stack works differently. Only one attitude can be stored with each interacting agent or pair of agents. New pieces of knowledge can gradually alter the attitude to another agent or interaction. When the capacity is reached, the least strongly held opinion is deleted. This models semantic memory (e.g. “Agent X is friendly”).

The ModelAt each time step, the agent decides either to:• Mate, based on age, energy and puberty• Give food, based on age and energy• Teach another agent, based on age and energy• Observe another event, based on age and energyThere are a number of time steps in a year.

GivingAgents can choose to give food to another agent. In doing so, their own energy depletes and the receiver’s energy increases. The receiver learns that the giver gave them food (a positive attitude).

TeachingAgents can choose to transfer a random piece of knowledge to another agent. The receiver also learns that the teacher chose to teach them something.

ObservingAgents can choose to learn any event that occurred in the current time step.

MatingIf an agent decides to mate, they choose another agent of the opposite sex to mate with, based on their knowledge. For each agent they know about, an overall attitude score is calculated based on the sum of the attitudes attached to each piece of knowledge and a weighting gene. Once the potential mate is chosen, they attempt to mate. The reciever may choose to accept or decline, based on their own attitudes towards the initiator. If they accept, then both agents expend energy and, if the receiver has not expired, they become pregnant and a new agent is added at the end of the year. An agent cannot become pregnant with more than one child at a time.

ReproductionSexual reproduction is modeled with genes chosen randomly from two parents of different sexes. Each gene represents either a slope or intercept for a decision variable. There is a small chance of drift.

Preliminary ResultsThe graph below shows some preliminary results from one run of the model. The Yellow line shows the population size, which slowly increases (on right scale). The solid lines represent the percentage of the population choosing various activities (Red = Mate, Blue = Observe, Green = Teach, Brown = Give). The dotted lines show the average proportion of choices to use episodic memory to store new knowledge compared to semantic memory, for adults (black) and children (brown).

The graph shows that children's average use of episodic memory is lower than adults'. This suggests that, over time, agents evolve to use mainly procedural memory as children, but then start using more episodic knowledge when they become adults. The robustness of these results need to be examined further.Discussion

The preliminary results agree with the hypothesis that the ability to store temporal social information using episodic memory during adulthood was selected. If the use of episodic memory conflicts or draws resources from semantic memory, this may explain the difficulty adults have in learning a second language.

This theory suggests a change over a much longer period than Hagen's and is also based on an adaptive advantage for declarative/episodic memory which is more likely to be selected than a neutral effect of procedural/semantic memory in adults.

The theory may be important in explaining linguistic diversity also. As Nettle (1999, p26) points out (under his 'Neutral model' of linguistic variation), in order for languages to change so as to become mutually unintelligible, two mechanisms are required. First is a source of variation. This is easy to find in both speech production by adults and learning patterns in children. The second type of mechanisms are amplifiers of variation - factors that maintain differences between two populations. This includes geographical isolation, but as Nettle points out, most societies have considerable levels of exposure to the languages of other cultures. This last point is very strong, but perhaps overlooks who is participating in cross-linguistic activities. If adults are the main interactors (trade, marriage, politics, war), then linguistic diversity may be maintained because they are poor at acquiring novel linguistic variants. That is, variation may be maintained if only the members who are acquiring the language (children) are isolated from other linguistic variants.

Since there is a huge amount of linguistic variation in the world, the selection process described in the model above should have occurred very early in language evolution, if not pre-linguistically.

Friday, 23 October 2009

A Replicated Typo recently posted on how bad the new Sci-Fi series Defying Gravity is. Charles Stross's blog on approaches to Sci-Fi is cited, basically making the point that a lot of Sci-Fis add lazers to ordinary dramas without thinking about the consequences for the characters.

It's a good point that many sci-fi programs seem to have fancy technology just for looking at, without any of it changing the way the characters interact or think about the world. However, there are some TV Sci-Fi shows that build the world from the ground up. My favourite example is the Ghost in the Shell spin-off TV series Stand Alone Complex. The show follows a team of anti-terrorists in the year 2030, where society has changed in response to the invention of e-brains and cybernetics. I often got the feeling that Masamune Shirow did not create a world, just write about one he happened to visit at some point.

There are two things that make SAC feel like a total immersion in a different world. Firstly, because it's animated, there is no difference between 'real' and 'CGI'. That is, suspension of disbelief is easier. Secondly, the new technology has a direct affect on the lives of the characters. Not only does the proliferation of cybernetics have an effect on what it means to be human, there are new ways to interact, and new ways to break the law (mind-hacking). Similarly, Orwell's invention of 'Thought-Crime' in Nineteen-Eighty-Four created a culture with new pressures.

As a side-note, also similar to Nineteen-Eighty-Four, SAC looks at the balance between public privacy and public security. However, the heroes of SAC are constantly hindered by lack of surveillance, and the viewer comes to empathise with their need for more information, quite contrary to the reader's response to Winston Smith's situation.

Back to Defying Gravity, it's difficult to see how a small crew going on a single journey aroud the solar system would change a culture. Perhaps Defying Gravity will eventually get around to this. I don't doubt that space travel can change a society's perception of itself, but how different is it from the moon landings for the average person?

Here we get to the root of the distinction between immersive worlds and drama-driven worlds. In the drama-driven world, the big change usually only occurs for a small, elite group of people. For example,Defying Gravity. In an immersive world, the big difference is global and the protagonists are more ordinary people who must survive in it. For example, Nineteen-Eighty-Four or Ghost in the Shell.

For a while my life ambition was to be the keeper of a labyrinth and confuse people. And I'm not talking about walking labyrinths used for meditation. Not even proper mazes that are fantastically designed (such as Tom's Mazes). I'm not even talking about puzzles just put there to infuriate everybody, such as this disastrous idea. I'm talking about a proper labyrinth with trips, traps and treasure.

Here's an old plan for the entrance. You enter a very high courtyard and see a tower in front of you. You climb the stairs and find yourself looking down on the courtyard (the walls of the courtyard are taller than the tower). And that's it. The trick is to realise that the turns in the staircase are actually slightly less than 90 degrees, meaning that, by the time you reach the height of the top of the tower you are slightly twisted, allowing the exit of the stairs to come out in a different, identical courtyard. To get through the entrance, you have to climb down the outside of the tower and leave through what looks like the entrance.

Thursday, 22 October 2009

Wednesday, 21 October 2009

I've been reading David Nettle's 'Linguistic Variation'. It brings up a very concerning issue:A common ancestor to humans lived about 140,000 years ago.Assuming a generation time of 25 years, that's 5,600 generations ago.There are about 6,500 mutually unintelligible languages in the world.

At first glance, this looks like there is at least one new language invented every generation! However, once a language has split into two, both can then go on to split into two other languages each. This means that it only takes 12.66 changes to create 6,500 different languages, or one new language per group every 442 generations, (or 11,000 years). Of course, this does not include languages that were created then died out, but even so, it's a lot less impressive than at first glance. In fact, what this suggests is that language transmission is actually pretty robust in the sense that it takes a myriadum (perhaps someone with better latincan correct me on this) for two sub-groups to develop so they can no longer understand each other. This agrees with Pagel, Atkinson & Meade's (2007) estimations of rates of change of single words over roughly the same time period.

Van Morrison's 'Moonlight' is considered one of the sexiest songs ever, but I always doubted the lines:

"Well I want to make love to you tonight,And I can't wait 'till the morning has come"

What's the hurry, Van? I thought you wanted to dance with me but are you, in fact, terribly embarrassed to be seen with me? You just want a quick in-and-out, wham-bam-thank-you-ma'am? Why are all the men in my life like this? Damn you, Van, keep your heart-strings, I'm going to dance with someone who'll stick around.

This hangs above my desk and reminds me that no one else is going to do my work for me. The image is taken pretty much as-is from the final shot of the final episode (here, with immense spoilers). It's one of the best endings of any TV show ever, with a beautifully subtle twist in the final seconds of the credits (noted also by BassInSpace), and this is my little tribute.

However, there's currently a live-action movie of Cowboy Beebop in production, with Keanu Reeves starring as Spike. So now I have a picture of Keanu Reeves on my wall. Not exactly something I had planned.

The best poker players can read other people like blogs. They know when you're bluffing and they know when you've got the cards to back your bet. A lucky player may be able to fool some of the people some of the time, but not all of the people all of the time. Given the continual possibility of bluffing, however, why do players pay any attention to other people's bets? Why do players strive to earn respect?

Let's play some Hold 'em. Imagine that a group of people are playing poker. At each round, they are dealt a hand. They know the strength of this hand on its own but that's not the whole story - they must figure out how good their hand is compared to everybody else. Even a pair of twos wins sometimes. If you think you have a good chance of winning, you'll put a bet down. This is your threat display - your signal to show you have a good hand. Some people will respect this and retreat without a fight. Others, however, may judge their hand to be better, and challenge you with a call. The cards play out, the winner is revealed and tops up his stack with the loser's chips.

The trick is to put out a bet that is proportionate to your chances of winning. Too small and lesser players may choose to challenge you and they might win by chance. So, there's no point in underplaying (unless you're trying to draw people into a trap, but this has its dangers). However, what stops people from putting too big of a bet? To start with, people may think you're bluffing, but a big enough risk will usually scare most people off. Too much of this behaviour, however, and the bets become meaningless. I've seen many people play their first hand of poker against hardened pros and win, mainly because the newbies don't respect the relationship between bet and threat. By devaluing the signaling currency, they make the system of betting irrelevant, forcing the pros to play more by chance, leveling the field. After a while, though, the newbies will harden and fall in line. The big question is why.

The problem of honesty in a poker game is analogous to the same problem in competing animals. Some animals, such as sparrows, have ways of signaling their fighting strength. 'Badges' such as the size or colouring of a patch of feathers on the breast indicates their dominance. Weak fighters will have small badge and strong fighters will have a big badge. The question facing evolutionary behaviourists is, why don't the strong fighters just evolve big badges and pretend to be good fighters, scaring off the competition? In other words, why not bet big with a bad hand? Why not bluff?

Lachmann, Szamado & Bergstrom (2001) point out that these systems differ in a major respect to other agnostic signals: The property they signal about is easy to verify. If you doubt a competitor can really fight well, you can just step up and peck him in the face; you can 'call'. Other animal signals, such as the size of a deer's antlers, are good indicators because they are directly linked to the property they signal about - a deer with big antlers not only has better weaponry but must also be strong enough to support such a heavy structure. Bird signals are disconnected from their meaning - they are fragile. Lachmann et al. suggest that bird signals are kept honest because anyone can challenge them. A bird signaling beyond his station - 'bluffing' - will eventually be found out and risk injury or death from a fight it cannot win. Cheaters are punished, bluffers will be revealed and lose their chips.

However, I'd like to make another observation - the fact that competing birds and poker players don't know how their strength compares to others is important. It means that you can only asses your own strength by observing the behaviours of others. A pair of jacks might seem like a good hand, but if someone raises your bet, you'll reassess the situation. (Another way of saying this is that the signaller cannot observe its own signal - birds can't see the feathers on their own chest)

I'm wondering if honesty falls out of this kind of interaction. To test this, I ran a model. You could see it as a model of poker:

A group of people are playing poker. They each get dealt a hand. This represents their individual strength. However, they cannot see other people's hands. Each player guesses his relative standing.

Each player also has a 'bet' that he places with the hand. This represents the signal to competitors.

Players play against each other, and can choose to call or fold to another player's bet.

If a player calls another, they compare their cards and the player with the best hand wins.

The winner increases his estimation of his standing in comparison with the group, and the loser lowers his estimation. The poker analogy is eroding, but bear with me.

After several rounds, the players are replaced by onlookers who adopt the strategies of the most successful players, with a little variation. This represents evolutionaryselection. Ok, so actually they inherit the player's cards as well, with a little variation. Yes, the poker analogy has gone bust.

Anyway, I predict that, over time, the player's bets will accurately reflect the player's hands. Good hands will place high bets and bad hands will place low bets. To switch back to signaling in birds, the size of the badge will correlate with the fighting ability of the bird.

Running this model reveals that, indeed, that is what happens. The graph below shows the correlation between badge size and fitness for 100 models with 50 individuals competing for 100 generations:

Point proven? Not so fast. Although the correlation between badge size and fighting ability does tend to increase, the standard deviations of badge sizes and fighting ability tend to decrease. That is, everybody becomes the same and there is no hierarchy. In this case, the signaling system has become redundant, and we can't say that honesty is stable. The problem lies in the amount of 'variation' with which players copy their 'parents' - that is, the genetic/ecological drift. Here's a graph of how the correlation varies as a function of the probability of a trait (e.g. player's hand or betting amount) changing and the amount it can change (each point is the mean of 10 runs on those settings):

We see that a high probability of a small amount of change leads to high correlations (stable honesty). However, the relationship is almost opposite for the standard deviation of badge size and fighting ability (each point in the graph below is the slope of a linear fit of the last 20 generations of 10 runs of the model with varying drift magnitude and probability, negative values indicate the hierarchy is eroding):Combining the three graphs, we find a space where an stable honest, hierarchical system is possible. The magic setting is one with a high probability of a small amount of change:

Ok, so what does this mean? Firstly, it's possible that honesty is inherent in a system where individuals are blind to their actual relative strength and must use the interactions with others to establish their place in the hierarchy. Furthermore, variation is key to maintaining this system. Since this is just a blog and not a paper, I can make wild unjustified claims, so here goes: Another ponderously stable signalling system is human language. Despite the obvious lying that goes on, most utterances are essentially honest. Also, human languages are hugely varied. Furthermore, children appear to be designed to handle a large variation in the input - including several languages at once. Perhaps language is built upon the same foundations as signalling systems in birds. After all, language is cheap and arbitrary and learned by interacting and observing behaviour, just like bird 'badges'.

To apease the poker fans that have made it this far, let's go back to the table. The variation in poker comes from the cards on the table - they provide an extra unknown factor which introduces an element of chance into the game. What all the pretty graphs suggest is that without this element, players would cease to rely on betting as an indication of how likely the player is to win. In other words, the betting would become irrelavent and pointless, and the game wouldn't work.

So next time you get upset when someone's bluff lucks-out on the river, just remember - it's all part of the game.

Sunday, 18 October 2009

Saturday, 17 October 2009

Watching The Raccoons intro as a child, I always wanted to play the computer game Cyril Sneer plays in his vault. Then I realised that software has become a lot more accessible since the late eighties. So here's a rough mock up!

Turns out it isn't so much fun. Ah well, another nostalgic hope dashed.

Friday, 16 October 2009

Every day on my way to the office, I pass a Big Issue salesperson. In traditional hawker fashion, he can be identified by his unique holler. However, he has prioritised a good sounding phrase over good grammar. A while ago he was shouting:

"Can I interest you to buy the Big Issue!"

I would usually use 'interest you in ...', but I was saved the possible embarrassment of correcting a homeless person's grammar because last week he had changed slightly:

"Can I interest you in the Big Issue!"

However, perhaps he thought that the hard-sell had gone out of the phrase, because he changed it again to:

"Can I interest you in buying the Big Issue!"

However, now he had ruined the neat rhythm of his initial chant and also lost the internal rhyme between 'I' and 'buy'. The next day he was back to his original call, albeit with a few 'in' variation slips. This pedaler is not alone in his tinkering with syntax, however. George Taylor writes about the old cries of Hawkers in London (here). Some include:

Swepe chimney swepe

Then shall no soote

Fall in your poridge pot.

A good sausage, a good,

Why do hawkers' cries take on these weird, ungrammatical forms? Imagining yourself as a Hawker, what you want is a phrase which is distinctive (to distinguish yourself from other competitors), easy to pronounce (you'll be saying it hundreds of times a day) and informative (so people know what you're selling). The last condition is perhaps the least important, since people will become familiar with your wares over time. This linguistic convention allowed the street hawkers of Damascus to use more elaborate calls (also from Taylor's article):

Appease your mother-in-law - FlowersIn the moonlight she stretched; she is cold - CucumbersFrom under the dew I gathered them! - Grapes

From these strange statements we understand that 'I have sausages/flowers/cucumbers to sell', also perhaps '... and mine are better'. The reason that good grammar seems to be abandoned is that language is primarily for communicating. People use what works.Indeed, I was waiting for a bus in Swansea once when I noticed that a noise which I previously thought was a problem with the air conditioning was actually an old woman. She let out short wails, starting quietly then rising and stopping suddenly. After about ten minutes, I figured she must have shortened "Western Mail and Echo" (the newspapers she was selling) to just the final hiccup of the phrase. This seems like the ultimate pragmatic use of language. All she was doing was getting people's attention, since it's pretty obvious what a woman in front of a large pile of newspapers is doing.

I've been a salesperson myself and some of my pitches atrophied so much that sometimes I gave said it wholesale to friends instead of 'hello' ('If you spend more than a fiver, you can get one of these fantastic DVDs for only ...').

I'm wondering if there's been any work about how street hawkers influence language. To start with, the rate of change of a word has been liked to word frequency (see Bybee, 2000, although there is evidence against this, e.g. Pagel, Atkinson & Meade, 2007). As Jurafsky (2003) points out, production and comprehension frequencies may not be the same, and one would expect an imbalance in hawkers.

In certain cities, hawker's calls must be a significant contributor to the input for children - I can still remember the scrap metal collector walking the lanes behind our house shouting 'Any old Iron', with a strange upward intonation at the end. How did this affect my language acquisition? Are there traces of French structure in my grammar from the onion sellers that used to call to my house?

Also street hawkers could act as accelerators or preservers of language change. The bottleneck of declaring your services in a short phrase in a noisy environment, coupled with constant repetition, could lead to a much higher rate of innovation and refinement of the linguistic code. At the same time, however, whole phrases are being protected from change by linguistic convention.

And as I'm thinking all this, I sail past the Big Issue vendor, lost in my own thoughts as he screams in my ear ...

Thursday, 15 October 2009

Inspired by the West Wing Episode 'Two Cathedrals'. The fiberboard gives it a nice rough texture. I'm quite pleased with it, but don't think it needed the stained glass patterns in the end. It's always nice to see fellow Westies (is that the collective?) light up as they walk into the room.